This application relates to and incorporated herein by reference Japanese Patent Application No. 2001-32861 filed on Feb. 8, 2001.
The present invention relates to an air intake device mainly used for an air intake system of an internal combustion engine for a vehicle.
As shown in FIG. 3, an air intake device proposed in JP-A-10-103089 has a metallic throttle body 103 and a resinous air intake duct 104. The throttle body 103 rotatably supports a throttle valve 101 through a valve shaft 102. The air intake duct 104 defines a hollow cylindrical air intake passage 105. The air intake duct 104 has an opening 104a that opens in a peripheral direction thereof, and the throttle body 103 is assembled onto the opening 104a. O-rings 110 are provided between contact surfaces of the throttle body 103 and the air intake duct 104.
In this kind of air intake device, in addition to the air intake duct, separate sealing members are required at an upstream side and a downstream side of the throttle to prevent an air leakage and communication with the outside air. Further, the throttle body is fixed with bolts. Therefore, the air intake device is upsized, and the number of components is increased. As a result, it is difficult to reduce a manufacturing cost. Furthermore, it is difficult to improve fuel efficiency due to weight increase and upsizing.
The present invention is made in view of the above problems, and it is an object to provide an air intake device suitable for reducing a manufacturing cost by downsizing and reductions of the numbers of assembly process and components, and reducing a weight by reducing an axial length of a throttle body, so that fuel efficiency of an engine is improved.
According to the present invention, a throttle body is directly connected to an air cleaner case and an intake manifold. Therefore, an air intake duct is not required, and it is unnecessary to fix the throttle body with bolts. Accordingly, the air intake device is downsized and the number of components is reduced.